Roborovski hamsters and Syrian hamsters don't have the same dietary preferences, and in an ideal situation should not be consuming the same diet. Dwarf hamsters eat dwarf hamster food, and Syrian hamster should eat Syrian hamster food. I would stress extreme caution with feeding the mix you have listed. It doesn't appear balanced, at all, and you are running the risk of severely jeopardising the health of your hamster.
For some further reading on homemade diets, I recommend reading
here.
If you want to purchase a pre-made diet, that is just as high quality as a homemade mix, I recommend
Getzoo - their mixes are far cheaper than Rodipets (who are daylight robbery, honestly) and they offer bulk options which is appealing to those who own multiple hamsters. You will go broke feeding 4 syrians rodipet and my Syrians in the past haven't been a huge fan of rodipet either, but they've all adored get zoo. Getzoo also offer mixes free of animal protein, so you can choose to add your hamsters preferred protein instead.